1. Field of the Invention
This invention relates to novel 2-alkoxy-3-oximinocycloalkene compounds and acid salts thereof and to a method for their production. The 2-alkoxy-3-oximinocycloalkene compounds disclosed herein are represented by the following generic formula: ##STR1## wherein R.sup.1 is a substituent selected from the group consisting of hydrogen, or aliphatic C.sub.1 to C.sub.10 radicals; R.sup.2 is the hydrocarbon radical of an aliphatic C.sub.1 to C.sub.10 alcohols or C.sub.5 -C.sub.6 cyclic alcohol and n is an integer of from 2 to 9. These compounds are prepared by nitrosating the corresponding cyclic ketone in the presence of an inert solvent having a dielectric constant of at least about 12, such as sulfur dioxide, sulfolane nitromethane, or nitrobenzene, an aliphatic C.sub.1 to C.sub.10 alcohol or C.sub.5 -C.sub.6 cyclic alcohol and at least one equivalent, preferably 2 to 5 equivalents, hydrochloric, hydrobromic, chlorosulfonic or strong Lewis acids such as borontrifluoride etherate or other strong mineral acid. These compounds are useful as fungicides and and precursors in the preparation of nylons or amino acids.
2. Description of the Prior Art
It is disclosed in our co-pending application Ser. No. 285,681 filed Sept. 1, 1972, now U.S. Pat. No. 3,857,510, that the carbon-carbon bond adjacent to a ketonic carbon can be cleaved with a nitrosating agent in the presence of alcohol and an aprotic solvent and in the absence of any supplemental acid. Nitrosation in the solvent system described in that application transforms the ketonic carbon into a terminal carboxylic acid ester group and an oxime group. Specifically, in the case of cyclic ketones, nitrosation in such a system results in the production of an .omega.-oximino acid ester.
Other previous attempts to nitrosate these cyclic ketones have resulted in the corresponding dinitrosated product, .alpha., .alpha.-dioximinocycloalkanones. Thus, heretofore an efficient process for the production of cyclic ketones which are directly mononitrosated without cleavage and which are desirable as synthetic intermediates was unknown in the art.